It's not Elixir, but I'm working through Jeremy Koppel's "Advanced Software Design Course". I've been coding for 22 years and it is definitely growing me.
Do have a look at the testimonials. He hits the nail on the head on many ideas I could intuit but didn't have words for.
I don't know of any books or speakers to compare him to. He's a unique bridge between academia and industry. I suppose you could say his teachings are available in the many academic papers he sources, but those papers are dense. His curation and contextualizion gets the ideas in a form I can comprehend and apply at work.